As aeronautical gas turbine engines of the free turbine turbo-shaft type find expanding applications for power generation applications due to their high achievable power densities, it is becoming increasing important to obtain the maximum transient response capability from the engines. In particular, many of these power generation applications are striving to obtain the most efficient and power dense power generation possible. This efficiency may rely on superconducting generators that have much longer excitation system time constants than the gas turbine engine. Although the two to four second time constant of the aircraft gas turbine engine will never satisfy the near instantaneous load-on and load-off transient capability of electrical systems, obtaining the maximum transient capability from the engine will greatly reduce the transient handling requirements for any associated energy storage and management systems, such as capacitors, batteries, flywheels and so forth. Furthermore, even if a conventional synchronous generator that can obtain very fast load-on and load-off power transients provides power generation, it may not be desirable to utilise this capability because of the transient response limitations of the engine. Ideally, the electrical load should follow the transient response of the gas turbine to maintain power turbine speed control.